Long term evolution (LTE) is long term evolution of a universal mobile telecommunications system (UTMS) technology standard established by a 3GPP organization. Key transmission technologies such as OFDM and multiple-antenna multiple-input multiple-output (MIMO) are introduced in an LTE system, thereby increasing a spectrum efficiency and a data transmission rate significantly, and enabling support of multiple types of bandwidth allocation. The LTE wireless network structure is more flattened, thereby decreasing a system time delay, reducing a network building cost and maintenance cost.
Initially, the LTE is designed to be only applied to a licensed frequency band, and respective operators occupy different licensed frequency bands. However, with rapid increasing of wireless broadband data within the world range, the LTE network develops rapidly. In order to improve the service quality, the operators pay attention to an unlicensed frequency band. In addition, making sufficient use of the unlicensed frequency band can also enable utilization of the existing LTE hardware resources of the operators and the device manufactures as much as possible. Therefore, it needs to develop a sharing technology for enabling multiple unlicensed communication systems to perform communications using the unlicensed frequency band simultaneously, thereby improving the frequency utilizing efficiency of the unlicensed frequency band.